As a manufacturing method of a sealed secondary battery, there has been conventionally known the technology that manufactures a sealed secondary battery by accommodating an electrode body in a container, providing an electrolyte in the container, temporality sealing the container, performing charge and discharge, and then fully sealing the container.
For example, in such a sealed secondary battery, a liquid injection opening provided in the container is sealed by using a rubber stopper or the like, and temporal sealing is carried out. Further, in the sealed secondary battery, a gas generated at the time of charge and discharge is discharged from the container by removing the rubber stopper, thereby avoiding deformation and damage of the container. Furthermore, in the sealed secondary battery, the liquid injection opening is sealed by welding a metal lid, and full sealing is effected. Through such a process, the sealed secondary battery is manufactured.